Lighter than air balloons may be formed from thin plastic films that include a gas barrier layer. Compared with conventional latex balloons, such films may reduce diffusion of lighter than air gases like helium, the gas typically used for inflating balloons, and give the balloons a more attractive appearance like a Valentine's Day heart shape, flower shapes, animal shapes, any famous character printing thereon and so on.
U.S. Pat. No. 4,077,588, the disclosure of which is totally incorporated by reference herein, describes in the Abstract thereof, a substantially permanently buoyant balloon suitable for use as a toy or in advertising. For example, a balloon is provided which includes an envelope containing a lighter than air gas such as helium. The envelope is made from attached panels of a non-elastomeric polymer sheet material carrying a continuous metal layer on at least one side thereof. The metal layer can either be a thin metal film contiguously bonded to the polymer, or can be metal which is vapor deposited over the surface of the polymer. The balloon itself is constructed so that the ratio of its volume taken to the two-thirds power divided by its surface area is in the range of from about 0.21 to about 0.01, and the weight of the envelope can range from about 2.6×10−4 gm/cm2 to about 1.7×10−2 gm/cm2. The envelope is preferably manufactured in a two dimensional “lay-flat” form in any desired two dimensional shape, unlike conventional balloon envelopes which are inherently three dimensional surfaces. Balloon envelopes having the above described volume to surface area ratio and made with the above described composite panel material will be maintained buoyant for an indefinite period of time when filled with the lighter than air gas.
U.S. Pat. No. 5,338,243, the disclosure of which is totally incorporated by reference herein, describes in the Abstract thereof, a balloon product, including at least two sheets, having a background depiction on one sheet and a foreground depiction on the other. The foreground depiction has a complementary relationship to the background depiction so as to provide a three-dimensional animated image.
U.S. Pat. No. 5,713,777, the disclosure of which is totally incorporated by reference herein, describes in the Abstract thereof, a non-latex inflatable toy in the form of a hand puppet. The puppet includes three sheets defining an inflatable chamber and a pocket for the hand of the user.
The appropriate components and process aspects of each of the foregoing U.S. patents may be selected for the present disclosure in embodiments thereof.
Although there have been attempts to improve the barrier properties of oriented polyester films in order to improve the lifetime of the balloons, there are other factors that also contribute to the lifetime of the balloons. More specifically, the leakage of helium gas occurs not only through the gas barrier film surface, but also through the sealing area where the two sheets are enveloped, especially when the balloon is fully inflated. The reason for this weak sealing of the oriented polyester film is that the surface of the oriented film is highly crystallized and shows poor sealing strength with the sealing layer. Another disadvantage of the oriented polyester film is that poor adhesion with the gas barrier layer occurs due to the same reason.
Further, the processes of the balloon fabrication are severe, involving abrasion and wet coating, which can reduce the effectiveness of the gas barrier layer by damaging and/or removing this layer. The gas barrier of the processed balloon should not be significantly degraded compared to the unprocessed substrate used. Furthermore, the balloon will be exposed to unexpected handling during the market use, folded, smashed, etc. under various climate conditions.